This invention relates to a fuel rail assembly for an internal combustion engine, especially for an automotive engine, equipped with an electronic fuel injection system. The fuel rail assembly delivers pressurized fuel supplied from a fuel pump toward intake passages or chambers via associated fuel injectors. The assembly is used to simplify installation of the fuel injectors and the fuel supply passages on the engine. This Invention is more particularly related to connecting constructions between the conduit (main pipe) having a fuel passage therein and branch pipes, and to a method of forming them.
Fuel rails are popularly used for electronic fuel injection systems of gasoline engines. The fuel rail delivers pressurized fuel from the conduit through several branch pipes toward a corresponding fuel injector. In diesel engines, the similar fuel rail is called a common rail and is usually designed to withstand extremely high pressure of diesel fuel. Due to the high pressure of fuel liquid, pressure fluctuations, mechanical vibrations, and dimensional changes under heat, there are drawbacks of fuel leakage from the connections between the conduit and the branch pipes.
Japanese patent unexamined publication Nos. 9-280464,9-287687, 11-257187, 2000-88167, and PCT publication WO96/18062 disclose connecting constructions between the conduit (main pipe) and the branch pipes of a fuel rail (gasoline engine) and a common rail (diesel engine).
U.S. Pat. No. 4,132,097 issued on Jan. 2, 1979 entitled “Method for forming collared holes” relates to a method for forming collared holes in a workplace.
U.S. Pat. No. 4,454,741 issued on Jun. 19, 1984 entitled “Flow drill for the provision of holes in sheet material” relates to a drill for the production of holes having a collar in metal sheet or metal tube walls.